A
UN project aimed to help millions - but it brought
them water contaminated with arsenic

Four decades after an
internationally funded move to dig tube wells across
the country massively backfired, huge numbers of
people still remain at higher risk of contracting
cancer and heart disease. The intellectual development
of untold numbers of children is also being held back
by the contamination of drinking water. Poor diet
exacerbates the risk.

Bangladesh's arsenic
crisis dates back to the 1970s when, in an effort to
improve the quality of drinking water and counter
diarrhoea, which was one of the country's biggest
killers of children, there was large-scale
international investment in building tube wells. It
was believed the wells would provide safe supplies for
families, otherwise dependent on dirty surface water
which was killing up to 250,000 children a year.

Yet the move,
spearheaded by the UN and the World Bank, was fatally
flawed. Although checks were carried out for certain
contaminants in the newly sourced water, it was not
tested for arsenic, which occurs naturally in the
Ganges and Brahmaputra deltas. By the early 1990s,
when it was found that up to half of 10 million tube
wells were contaminated with arsenic, Bangladesh was
confronting a huge problem. The World Health
Organisation called it "the largest mass poisoning of
a population in history... The scale of the
environmental disaster is greater than any seen
before; it is beyond the accidents in Bhopal, India,
in 1984, and Chernobyl, Ukraine, in 1986".

Some subsequent
studies predicted that, ultimately, one person in 10
who drinks water from the arsenical wells would go on
to die from lung, bladder or skin cancer. Even though
some of these conditions take decades to develop, by
2004, about 3,000 people a year were dying from
arsenic-related cancers.

Since the 1990s,
organisations such as Unicef have led the effort to
develop and provide alternative sources of water, such
as collecting rainwater and filtering surface water.
Slowly, the percentage of families exposed to
contaminated water has fallen. But a survey conducted
by Unicef last year found that 13 per cent of people
are still using contaminated water. "That equates to
20 million people," says Yan Zheng, a Unicef arsenic
specialist based in Dhaka. "The health impacts vary.
The skin lesions that arsenic causes are well
recognised by the villagers. But the cancer and
cardiovascular diseases are still not fully recognised
by the villagers and some health professionals." Ms
Zheng says a recent study showed significantly higher
death rates for those exposed to arsenic: "It was as
you would expect - the higher the exposure, the higher
the risk.".

Government and UN
officials will publish a new report tomorrow calling
for urgent action to tackle what remains a huge
problem of contamination, both from drinking water and
from crops such as rice that are irrigated with
contaminated water. According to the report, being
released to coincide with World Water Day, arsenic
poses health risks to a significant proportion of the
population, though children are particularly
vulnerable.

The skin lesions
caused by arsenicosis are just the first sign of many
possibly fatal health problems. The lesions still
attract widespread social stigma in Bangladesh, with
many people until recently believing they were the
result of a curse.

"Urgent action is
needed to refocus the attention of the nation towards
an arsenic-safe environment," says Renata Lok
Dessallien, the UN chief in Bangladesh. "Concerted
efforts by the government and all stakeholders are
necessary to reinvigorate arsenic monitoring and
mitigation efforts, and to conduct comprehensive
research on emerging threats."

The arsenic
contaminating so much of Bangladesh's water occurs
naturally in the water courses of the rivers that
sustain hundreds of millions of people. Many
underground sources around the world suffer from
arsenic contamination and there have been health
issues in countries ranging from Argentina to Taiwan
and India. There is also considerable arsenic
contamination in parts of the US.

In Bangladesh, a
fierce row continues to rage over the responsibility
for the massive contamination. While aid groups and
the UN insist their testing at the time met
international standards, others have argued that there
should have been a more thorough awareness of the
local geology and topography. Yet more have said that
the UN and the World Bank were slow to acknowledge
their role in the tragedy.

Dipankar Chakraborti,
of the Jadavpur University in West Bengal and a
leading expert, says the level of arsenic
contamination in Bangladesh is worse than anywhere
else globally. He says the international bodies have
never fully acknowledged their role in a crisis that
will be played out for years to come. "It is a major
problem," he says. "We have found that when we went
back to people with skin lesions whom we interviewed
15 years ago, about 30 per cent of them had developed
some sort of cancer."

Last year scientists
concluded that arsenic entered the water in tube wells
as a result of thousands of ponds that were dug across
Bangladesh to provide soil for flood protection.
Disturbing the ground released the organic carbon,
which in turn causes arsenic to leach from sediments.
The scientists from MIT in Boston concluded that one
solution would be to dig "deeper drinking-water wells,
below the influence of the ponds".

Meanwhile, educating
the public about the dangers of arsenic poisoning, and
disabusing them of the widespread idea that its
effects are the result of a curse, or infectious, is
essential. "Raising awareness among people on the
danger of arsenic is essential," says Bangladesh's
minister of health, Dr A F M Ruhal Haque. "Health
workers can disseminate this message, while the
government will continue to invest in screening and
treatment of arsenicosis patients in affected
districts."

Britain's
toxic beer

Arsenic was a
pervasive contaminant in Britain and the US in the
19th century. It was used in wallpaper, fabric dyes,
and even as a colouring in confectionery.

One of the worst
instances of man-made arsenical poisoning came in
Lancashire in late 1900. Large numbers of people in
the Manchester and Salford areas displayed symptoms of
what was thought to be simple over-indulgence. But, as
the cases mounted, and people began to turn up with
blackened skin and other tell-tale signs, arsenic
poisoning was suspected. This was confirmed, and
eventually traced to the firm that supplied sugar used
in brewing.

Before the poisonings
had run their course, more than 6,000 people had been
affected, and 80 of these died. The episode was
instrumental in securing more rigorous legislation on
food safety.